The present invention relates to generally a fuel distribution system for a spark ignition engine and more particularly a fuel distribution system therefor of the type for continuously injecting the fuel at a relatively low pressure into an intake air pipe of the individual cylinder.
When the fuel distribution system of the type described is used in conjunction with a multicylinder engine, the fuel in quantity in proportion to the intake air quantity must be injected into the intake air pipes of the individual cylinders of the engine, and the quantity of the fuel to be introduced into the individual cylinders must be uniformly controlled with higher accuracy. That is, the fuel must be evenly distributed in order to improve the engine operation and fuel economy and to reduce the toxious exhaust gas emissions. For this purpose, there have been proposed various fuel distribution systems, but in every system it is essential to use the fuel injection nozzles with the uniform characteristics. However, in view of the present levels of the manufacturing techniques it is impossible or extremely difficult to fabricate such fuel injection nozzles so that there arise the problems of interchangeability and readjustment of the whole system after the damaged fuel injection nozzles have been replaced. In one system, a fuel metering valve is provided for each fuel injection nozzle, but the flow rate of the fuel passing through the metering valve is very small in quantity so that the metering valve complex in construction must be used in order to control the fuel flow rate with higher accuracy, thus resulting in the increase in cost.